1. Field of the Invention
The present invention relates to a large-capacity recording medium, a method and apparatus for reproducing information from a large-capacity recording medium, and a method and apparatus for recording information on a large-capacity recording medium. More particularly, it relates to an optical disk on which at least one movie, audio information representing various languages one of which can be selected for the movie, a plurality of sub-pictures and a number of audio streams are recorded, and from which any item of information recorded can be reproduced, to a method and apparatus which reproduce information from such an optical disk, and to a method and apparatus for recording information on an optical disk of high recording density.
2. Description of the Related Art
Optical disks, generally known as compact disks (CDs), have been developed. It is considered difficult to record movie information on or reproduce it from a CD, because of the limited storage capacity of the CD. Researches have been conducted on optical disks of a new type capable of recording movie information at high density. Optical disks are now at development stage.
It is well expected that several movies, not one movie only, can be recorded on an optical disk of the new type, which has a large recording capacity, and that each movie recorded can be played back from in various ways. For instance, an American movie recorded can be played back, not dubbed into any other language. Alternatively, the American movie can be reproduced, dubbed into any other language (e.g., Japanese), along with English subtitles will be superimposed on the images reproduced. Still alternatively, the movie may played back in one of various "versions," which the user has selected; for example, it may be played back, except the violent scenes, if the user does not wish to see such scenes.
To play back a movie from the optical disk in various ways, it is necessary to record various information items representing the movie such that any information item may be selected and reproduced. To select and reproduce one or some movie information items among the may recorded on the optical disk, selection information for use in selecting desired movie information items must be recorded on the optical disk, as well.
The existing CDs comply with the ISO Standards which were made on the assumption that it suffices for an optical disk to have a storage capacity of 4 GB at most. This is why most CDs available at present have a storage capacity of less than 1 GB. Inevitably, data amounting to more than 4 GB cannot be managed by using the conventional optical disk. Large-capacity optical disks have been recently developed, each capable of recording a data item which exceeds 4 GB. It is now demanded that a system be provided which can efficiently manage a data item more massive than 4 GB (e.g., movie information) recorded on a large-capacity optical disk and which can reproduce the data from the optical disk at high speed and in various ways.